A resonance type non-contact charging system is disclosed that includes a resonance system. The resonance system has a primary side resonance coil, a secondary side resonance coil, a reflected power detecting section, a power converting section having a DC/DC converter, and a battery. The charging system has a controlling section that controls the DC/DC converter. The controlling section controls the duty cycle of the DC/DC converter based on detection result of the reflected power detecting section such that the input impedance of the resonance system at the resonant frequency and the output impedance of a high-frequency power source match each other.